CN116792736A

CN116792736A - Steam generating apparatus

Info

Publication number: CN116792736A
Application number: CN202310764309.7A
Authority: CN
Inventors: 朱高涛; 段毅; 袁飞; 钱湖涛
Original assignee: Anhui Rejing Boiler Co ltd
Current assignee: Anhui Rejing Boiler Co ltd
Priority date: 2023-06-25
Filing date: 2023-06-25
Publication date: 2023-09-22

Abstract

Disclosed is a steam generating apparatus capable of preventing dry burning damage of a heat exchange tube, comprising: a burner; a first heat exchange assembly provided with a combustion chamber for the combustion of the burner, and a first flue gas flow passage and a main heat exchange flow passage are defined; the water of the main heat exchange flow channel and the flue gas heat exchange heating part of the first flue gas flow channel are vaporized, and steam-water mixed fluid with the temperature of more than 90 ℃ is output; a second heat exchange assembly defining a second flue gas flow path and a steam generation flow path; the second flue gas flow channel is communicated with the downstream of the first flue gas flow channel in the flue gas flow direction, and the steam generation flow channel is communicated with the downstream of the main heat exchange flow channel in the water flow direction; the steam-water mixed fluid of the steam generation flow channel exchanges heat with the smoke of the second smoke flow channel to form steam; the second heat exchange assembly has a steam output for outputting steam.

Description

Steam generating apparatus

Technical Field

The present disclosure relates to the field of steam generation technologies, and in particular, to a steam generation device.

Background

Under the call of national energy conservation and emission reduction, the steam generating equipment accelerates the development to the full premix condensation type with high efficiency and low emission. Especially, the inspection-free/newspaper-free through-flow gas steam generator has the advantages of faster steam generation speed, more energy conservation and environmental protection compared with the traditional steam boiler, no need of installation and inspection and boiler annual examination, is widely favored by the market, and is widely applied to national production and life, such as hotels, guesthouses, food processing, textile, chemical industry, feed processing and other industries.

However, the real water volume of the through-flow gas steam generator in the existing market is commonly exceeded, and especially after the execution of the through-flow gas steam generator is issued by the 2020-edition boiler rule, a water volume calculation mode is defined, namely, the total geometric volume in an inlet and an outlet of a steam-water system comprises the total pressure-bearing space internal volume from the outlet of a water supply pump to the steam outlet of equipment, based on the calculation mode, the water volume of most of the through-flow gas steam generators in the existing market is far more than 30 liters, the through-flow gas steam generator does not meet the boiler rule inspection-free standard, and a condenser installed in the equipment is used as a pressure-bearing component, so that the pressure-bearing requirement is higher, and no small potential safety hazard exists.

In order to solve the problems, the invention patent application of a novel through-flow steam generator or a steam boiler and a heat exchange unit thereof disclosed in the publication No. CN114508745A is filed by a hot well energy-saving technology, a single-circle vertical pipe structure is adopted to be matched with a burner to realize a small-volume steam generator structure, the steam generating equipment disclosed in the publication No. CN115614722A is further filed and an operation method thereof are further filed, and a double-pump operation system is adopted to be matched with a buffer in the invention patent, so that the cavitation problem is solved.

Although the small-volume steam generator disclosed in the above patent can solve the technical problem of producing full-volume high-quality steam under the condition of small volume, in actual use, the long-time high-temperature high-pressure continuous operation can not achieve the same service life as the traditional water tube boiler, and the problem of easy dry burning damage at the upper part of the heat exchanger can still be solved.

Along with further research, it is found that the vertical pipe type heat exchange unit of the small-volume through-flow steam boiler (steam generator) directly surrounds the outside of the burner, a steam-water interface exists inside the vertical heat exchange pipe, and due to the fact that the overlapping area of the burner and the heat exchange pipe is large in the requirement of small volume, the phenomenon that the steam-water interface cannot be higher than the fire interface of the burner exists, a certain length of steam section of the heat exchange pipe is exposed in the combustion chamber, and the steam section directly corresponds to the combustion area of the burner. However, the specific heat capacity of the water vapor is far smaller than that of water, so that the heat absorption capacity of the steam section is weak, continuous dry heating is formed, the heat exchange tube is damaged by dry heating, and the service life of the steam generator is shortened.

Disclosure of Invention

In view of the above, it is an object of the present disclosure to provide a steam generating apparatus that can avoid dry burning damage of heat exchange tubes.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a steam generating apparatus, comprising:

a burner;

a first heat exchange assembly provided with a combustion chamber for the combustion of the burner, and a first flue gas flow passage and a main heat exchange flow passage are defined; the water of the main heat exchange flow channel and the flue gas heat exchange heating part of the first flue gas flow channel are vaporized, and steam-water mixed fluid with the temperature of more than 90 ℃ is output;

A second heat exchange assembly defining a second flue gas flow path and a steam generation flow path; the second flue gas flow channel is communicated with the downstream of the first flue gas flow channel in the flue gas flow direction, and the steam generation flow channel is communicated with the downstream of the main heat exchange flow channel in the water flow direction; the steam-water mixed fluid of the steam generation flow channel exchanges heat with the smoke of the second smoke flow channel to form steam; the second heat exchange assembly has a steam output for outputting steam.

As a preferred embodiment, the second heat exchange assembly is provided with a boiler water level gauge.

As a preferred embodiment, a third heat exchange assembly is also provided; the third heat exchange assembly is limited with a third flue gas flow passage and a preheating flow passage; the third flue gas flow channel is communicated with the downstream of the second flue gas flow channel in the flue gas flow direction; the preheating flow passage is communicated with the upstream of the main heat exchange flow passage in the water flow direction; and the water in the preheating flow passage exchanges heat with the smoke in the third smoke flow passage to heat and preheat.

As a preferred embodiment, the third heat exchange assembly is a condensing heat exchanger having a first water inlet end and a first water outlet end; a first water pump is communicated with the upstream of the first water inlet end;

The first heat exchange assembly is provided with a second water inlet end and a second water outlet end; a second water pump is connected in series between the first water inlet end and the second water inlet end; the lift of the second water pump is larger than that of the first water pump; the lift of the first water pump is larger than the water resistance of the third heat exchange assembly.

As a preferred embodiment, the first heat exchange assembly includes a cylindrical housing, and a first heat exchange unit inside the cylindrical housing; the first heat exchange unit is communicated between the second water inlet end and the second water outlet end; the first heat exchange unit is limited with a plurality of first vertical heat exchange pipes of the main heat exchange flow channel, and the first vertical heat exchange pipes surround the combustion chamber where the combustor burns.

As a preferred embodiment, the first heat exchange assembly is further provided with an inner rod inside at least one of the first vertical heat exchange tubes; a water storage space is formed between the outer wall of the inner rod and the inner wall of the heat exchange tube; the length of the inner rod along the length direction of the heat exchange tube is more than 20% of the length of the heat exchange tube.

As a preferred embodiment, the second heat exchange assembly comprises a housing and a second heat exchange unit located within the housing; the second heat exchange unit includes a plurality of second vertical heat exchange tubes defining the steam generation flow passage; the second heat exchange assembly is provided with a third water inlet end communicated with the second water inlet end; the third water inlet end is positioned at the lower end of the second heat exchange unit.

As a preferred embodiment, the upper end of the second heat exchange component is provided with an upper header communicated with the steam output end, and the lower end of the second heat exchange component is provided with a lower header communicated with the third water inlet end; the upper ends of the second vertical heat exchange tubes are communicated with the upper header, and the lower ends of the second vertical heat exchange tubes are communicated with the lower header.

As a preferred embodiment, the second heat exchange assembly is provided with a steam-water separation assembly at a position which is 50% higher than the second vertical heat exchange tube inside the at least one second vertical heat exchange tube; the steam-water separation assembly is configured to form a steam-water fluid barrier for at least partially flowing along the length direction of the heat exchange tubes and has a fluid flow path with an upper end for fluid output and a lower end for fluid input; the length of the steam-water separation component along the length direction of the heat exchange tube is more than 1% of the length of the heat exchange tube and less than 30% of the length of the heat exchange tube, or the length along the length direction of the heat exchange tube is 5mm-500mm.

As a preferred embodiment, the main heat exchange flow channel surrounds the combustion chamber; the steam generation flow passage is positioned outside the first heat exchange assembly.

The beneficial effects are that:

the steam generating device of one embodiment of the application is additionally provided with a second heat exchange component between the condensing heat exchanger and the first heat exchange component (the steam generating body), and the second heat exchange component exchanges heat with the incoming flow of the flue gas to form secondary vaporization, and provides a steam-water separation place. The second heat exchange assembly is far away from high-temperature flame in comparison with the first heat exchange assembly, the steam section of the heat exchange tube is far away from high-temperature flame, high-temperature dry combustion is avoided, the steam quality can be guaranteed, and the service life can be guaranteed.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a perspective view of a steam generating apparatus according to an embodiment of the present disclosure;

FIG. 2 is a perspective view of a steam generating apparatus according to an embodiment of the present disclosure;

FIG. 3 is another view of FIG. 2;

FIG. 4 is a front view of FIG. 2;

FIG. 5 is a perspective view of the second heat exchange assembly of FIG. 2;

FIG. 6 is another view of FIG. 5;

FIG. 7 is a schematic view of the second vertical heat exchange tube arrangement of FIG. 5;

fig. 8 is a perspective structural view of a steam generating apparatus according to another embodiment of the present disclosure.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, shall fall within the scope of the invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

One embodiment of the present disclosure provides a steam generating apparatus that is suitable for use with, but not limited to, a no-go steam generator or a steam boiler. Preferably, the water volume of the steam generating device is below 50L, and further, the water volume of the steam generating device is below 30L.

Referring to fig. 1, the steam generating apparatus of the present embodiment includes: a burner, a first heat exchange assembly 50, a second heat exchange assembly 70, a first water pump 10 and a second water pump 40. Wherein the first heat exchange assembly 50 defines a first flue gas flow path and a primary heat exchange flow path. And the water in the main heat exchange flow channel exchanges heat with the flue gas in the first flue gas flow channel to raise the temperature, so that a steam-water mixed fluid (steam-water mixture) is formed in the main heat exchange flow channel. When the steam-water mixed fluid is output by the main heat exchange flow channel, the temperature of the steam-water mixed fluid is above 90 ℃. The water in the vapor-water mixture is 15% or more, and the liquid-phase water in the vapor-water mixture output from the first heat exchanger 50 is 40% by way of example, so that the temperature of the water in the vapor-water mixture is raised and vaporized by half or more by weight in the first heat exchanger 50. In addition, the (liquid phase) water vapor in the steam-water mixed fluid is more than 50%.

The second heat exchange assembly 70 defines a second flue gas flow path and a steam generation flow path. The second flue gas flow passage is communicated with the downstream of the first flue gas flow passage in the flue gas flow direction. The steam generation flow passage is communicated with the downstream of the main heat exchange flow passage in the water flow direction. And the water (steam-water mixed fluid) of the steam generation flow channel exchanges heat with the smoke of the second smoke flow channel to form steam. The second heat exchange assembly 70 has a steam output 71 for outputting steam. Wherein, the steam-water mixed fluid heats and vaporizes the residual water in the steam generation flow channel, and the dryness of the steam output by the second heat exchange assembly (the steam output end 71) is more than 90%. Preferably, the steam dryness of the steam outputted from the steam output end 71 is 98% or more.

The water volume of the steam generating device of the embodiment can be lower than 50 liters, the dryness of the steam can reach more than 95% (up to 98%), the evaporation capacity can reach 1000kg/h, and the energy-saving effect is improved by more than 30% compared with that of the traditional boiler.

The first heat exchange assembly 50 defines a combustion chamber therein in which the burner burns to form a high temperature flame and outputs a high temperature flue gas. The main heat exchange flow passage surrounds the outside of the combustion chamber, the first vertical heat exchange tube is used as a carrier of the main heat exchange flow passage, the surrounding combustion space forms the combustion chamber, and the burner is a cylindrical burner and extends into the combustion chamber. The steam generating flow path is located outside the first heat exchange assembly 50, away from the high temperature flame.

The steam generating device is further provided with a third heat exchange assembly 20. The third heat exchange assembly 20 defines a third flue gas flow path (flue gas flow space) and a preheating flow path (water flow space). The third flue gas flow passage is communicated with the downstream of the second flue gas flow passage in the flue gas flow direction. And the water in the preheating flow passage exchanges heat with the smoke in the third smoke flow passage to heat and preheat. The temperature of the preheated water output by the third heat exchange assembly 20 is above 60 ℃. The preheating flow passage is communicated with the upstream of the main heat exchange flow passage in the water flow direction. The preheating runner is provided with a first water inlet end and a first water outlet end. In this embodiment, the first, second, and third water inlet ends and the first and second water outlet ends are configured with flange connection structures.

The steam heat exchange equipment of the embodiment adopts double-pump relay heat exchange, the energy economizer (the third heat exchange component 20) is not pressurized, the use safety coefficient is improved, and the service life is prolonged. The third heat exchange assembly 20 is a condensing heat exchanger having a first water inlet end and a first water outlet end; the upstream of the first water inlet end is communicated with a first water pump 10. The first heat exchange assembly 50 has a second water inlet end 52 and a second water outlet end 53. A second water pump 40 is connected in series between the first water outlet end and the second water inlet end 52; the lift of the second water pump 40 is larger than that of the first water pump 10; the lift of the first water pump 10 is greater than the water resistance of the third heat exchange assembly 20.

The steam generating device of this embodiment sets up dual pump operation, through first water pump 10 before third heat exchange assembly 20, with the water resistance offset of third heat exchange assembly 20, set up in the second water pump 40 of third heat exchange assembly 20 (along the rivers direction) low reaches because the water resistance (pipeline resistance) of third heat exchange assembly 20 offsets in order to be offset by first water pump 10 when the operation, and then third heat exchange assembly 20 is less even eliminated to the pumping efficiency influence of second water pump 40, and then can in time supply water to first heat exchange assembly 50 (furnace body) under dual pump effect, satisfy first heat exchange assembly 50 to water level control's requirement.

And, the third heat exchange assembly 20 is located at the upstream of the second water pump 40, no bearing design is needed, and then the third heat exchange assembly 20 (economizer) does not belong to a bearing device, so that the bearing water volume can be improved better, the internal geometric volume between the water outlet end of the second water pump 40 and the steam output end 71 of the second heat exchange assembly 70 of the steam generating equipment is below 30L, and the influence on the steam generation speed and the evaporation capacity of the steam generator or the steam boiler is avoided on the basis of realizing real safety and no check.

To avoid increasing the water volume, the water in the primary heat exchange flow channel of the first heat exchange assembly 50 undergoes a phase change to form water vapor, and a steam-water mixed fluid is formed in the first heat exchange assembly 50. Part of the water in the first heat exchange assembly 50 is vaporized to form water vapor through heat exchange with the high-temperature flue gas, and part of the liquid water falls down faster than the water vapor due to gravity, so that the water vapor is prevented from being separated from the downstream water vapor, and a steam-water mixed fluid is formed. The second outlet end 53 of the first heat exchange assembly 50 outputs a steam-water mixed fluid.

To avoid dry heating caused by steam-water separation of the first heat exchange assembly 50, the second water inlet end 52 of the first heat exchange assembly 50 is higher than the second water outlet end 53. Further, the second water inlet end 52 is located at the upper end of the first heat exchange assembly 50, and the second water outlet end 53 is located at the lower end of the first heat exchange assembly and is in communication with the third water inlet end 73 via a conduit 68. Alternatively, as shown in the embodiment of fig. 8, the second water outlet 53 is located at the upper end of the first heat exchange assembly 50 and is in communication with the third water inlet 73 via the conduit 68', and at this time, the second water inlet 52 of the first heat exchange assembly 50 is located at the lower end thereof.

The second heat exchange assembly 70 is connected to the downstream of the first heat exchange assembly 50, and is directly input into the steam-water mixed fluid formed by the first heat exchange assembly 50, so that the second heat exchange assembly 70 can be prevented from forming a steam superheater, the requirement of saturated steam cannot be met, and meanwhile, the heat absorption capacity of the second heat exchange assembly 70 is reduced, the overheating problem is generated, and the service life is influenced.

In this embodiment, the second heat exchange assembly 70 exchanges heat with the incoming flue gas stream to form secondary vaporization on the one hand and provides a steam-water separation site on the other hand. The second heat exchange assembly 70 is far away from the high temperature flame compared with the first heat exchange assembly 50, and the steam section of the heat exchange tube is far away from the high temperature flame, so that dry burning is avoided, the steam quality can be ensured, and the service life can be ensured.

The steam generating device of the embodiment is added with the second heat exchange component 70, so that the steam-water interface can be far away from the fire interface (high-temperature flame), and the increase of the water volume can be avoided, thereby avoiding the dry burning damage of the heat exchange tube. It is conceivable that the structure of the steam generating device can be still applied to the steam generating device with large volume, so that the problem of dry burning is avoided.

In this embodiment, the steam generating device is a through-flow steam generator. The first heat exchange assembly 50 includes a cylindrical housing, and a first heat exchange unit inside the cylindrical housing. The first heat exchange unit is communicated between the second water inlet end 52 and the second water outlet end 53. The first heat exchange unit comprises a plurality of first vertical heat exchange tubes which are arranged in parallel and are limited with the main heat exchange flow passage. The first heat exchange assembly 50 acts as a primary heat exchanger that provides a primary heat exchange site for steam generation, with the length of the first vertical heat exchange tubes being greater than the length of the second vertical heat exchange tubes 711 to ensure that the incoming water absorbs heat to a partial vaporization at the first heat exchange assembly 50. The lower ends of the first vertical heat exchange tubes are positioned below the second vertical heat exchange tubes 711, and the upper ends of the first vertical heat exchange tubes are higher than the upper ends of the second vertical heat exchange tubes 711. And a flow blocking structure can be further arranged in the first vertical heat exchange tube so as to avoid too high flow speed and improve the heat exchange effect. The flow blocking structure can be a flow blocking baffle plate in the first vertical heat exchange tube, and the flow blocking baffle plate can also mix steam and water so as to avoid steam and water separation.

In order to avoid the water volume exceeding 30 liters, the first vertical heat exchange tube is also internally provided with an inner rod. Wherein, increase the interior pole at first vertical heat exchange tube inside, the interior pole is solid pole structure or with the blind pipe structure (seal pipe) of first vertical heat exchange tube inside each other not communicating pipe. The water storage volume in the first vertical heat exchange tube is reduced through the arrangement of the inner rod. The inner rod is a sealing pipe with upper and lower ends respectively sealed by an upper sealing plate and a lower sealing plate, and is coaxially arranged in the first vertical heat exchange pipe. In addition, the inner rod can be arranged eccentrically outwards in the radial direction, so that more water is reserved on the inner side in the radial direction for full heat exchange.

In this embodiment, a water storage space (water storage annulus) is formed between the outer wall of the inner rod and the inner wall of the first vertical heat exchange tube. The length of the inner rod along the length direction of the first vertical heat exchange tube (the length of the inner rod in the first vertical heat exchange tube is called as the axial direction for short) is more than 20% of the length of the heat exchange tube, and further, the length of the inner rod is more than 80% of the length of the heat exchange tube.

Compared with the prior art that the single main heat exchanger device of the existing steam generating device focuses on the state of the gas-liquid mixed fluid output by the first heat exchange unit, the length of the inner rod of the embodiment is more than 50% of the length of the first vertical heat exchange tube, and even more than 80% of the length of the first vertical heat exchange tube.

Such as in one possible embodiment, the inner rod extends from the lower end of the first vertical heat exchange tube to the upper end of the first vertical heat exchange tube, and a water storage annulus of equal length is built inside the first vertical heat exchange tube, so that the water volume under the double pressure-bearing heat exchanger is reduced to the maximum extent. Through the existence of interior pole, reduce the inside evaporation space of first vertical heat exchange tube, avoid water excessive evaporation, moreover the unstable beat of water more easily mixes with the vapor of vaporization, forms expected catch water, and then moves main evaporation place to second heat transfer module 70, forms the steam-water separation interface (can be surveyd by the boiler fluviograph) in second heat transfer module 70.

The water in the first heat exchange assembly 50 forms water vapor, which is not separated from the water phase to form mixed water with larger vapor content or water vapor with larger water content, and no obvious water-water interface is formed in the first vertical heat exchange tube of the first heat exchange assembly 50, so that the water level meter 59 is communicated to monitor the water level.

The second water inlet end 52 is communicated with the upper end of the second heat exchange assembly 70, and the second water outlet end 53 is communicated with the lower end of the second heat exchange assembly 70; alternatively, the second water inlet end 52 is connected to the lower end of the second heat exchange assembly 70, and the second water outlet end 53 is connected to the upper end of the second heat exchange assembly 70.

In this embodiment, the second heat exchange assembly 70 includes a housing 700 and a second heat exchange unit 710 located within the housing; the second heat exchange unit 710 includes a plurality of parallel arranged second vertical heat exchange pipes 711 defining the steam generation flow path. The second vertical heat exchange pipe 711 has a straight pipe structure. The third heat exchange assembly 20 has a third water inlet end 73; the third water inlet end 73 is communicated with the lower end of the second heat exchange unit 710. The second heat exchange assembly 70 is located between the first heat exchange assembly 50 and the third heat exchange assembly 20. Preferably, the second vertical heat exchange tube 711 may also be a fin heat exchange tube, so as to improve heat exchange efficiency.

The second heat exchange assembly 70 is provided with a boiler water level gauge 79. As an alternative embodiment, as shown in fig. 2 and 3, the first heat exchange assembly 50 is provided with a body boiler water level gauge 79. The boiler water level gauge 79 and the body boiler water level gauge 59 can be liquid level gauges disclosed in publication number CN218846111U by Anhui heat scene boiler limited company, and are not described here. The water level of the second heat exchange assembly 70 is monitored by the boiler water level gauge 79, so that the phenomenon that the steam-water interface of the second heat exchange assembly 70 is too high or too low is avoided, and the steam quality of the second heat exchange assembly 70 is further ensured.

The liquid level (vapor-water interface) of the second heat exchange assembly 70 is between 20% -30% of the second vertical heat exchange tube height and 90% of the second vertical heat exchange tube height as observable by the boiler water level gauge 79. That is, the liquid level in the second vertical heat exchange tube is at least 20% -30% of the height of the heat exchange tube, and the highest liquid level is at about 90% of the height of the heat exchange tube, preferably, the liquid level in the second vertical heat exchange tube is at 40% -70% of the height of the heat exchange tube, so as to provide enough vaporization space and steam-water separation space, and improve the quality of the output steam.

As shown in fig. 5 and 6, the second heat exchange assembly 70 has an upper header 77 at an upper end and a lower header 76 at a lower end. The plurality of second vertical heat exchange tubes 711 have upper ends communicating with the upper header 77 and lower ends communicating with the lower header 76. The third water inlet end 73 is communicated with the lower header 76, and the steam output end 71 is communicated with the upper header 77. The upper header 77 has an upper communication space, and a plurality of second vertical heat exchange tubes 711 are simultaneously introduced into the upper header 77 while inputting steam into the upper header 77. The lower header 76 has a lower communication space, through which the vapor-water mixed fluid discharged from the first heat exchange assembly 50 is introduced, and is simultaneously introduced into the plurality of second vertical heat exchange tubes 711.

In this embodiment, the second heat exchange assembly 70 is provided with a steam-water separation assembly, which separates the steam from the water and improves the dryness of the steam. The steam-water separation module may be disposed in the upper header 77, such as with an orifice plate structure. The steam-water separation assembly may be provided in the second vertical heat exchange pipe 711 in a structure such as a spiral plate. The steam-water separation component is located above the steam-water interface in the case of the second vertical heat exchange tube 711, and is disposed near the upper end of the second vertical heat exchange tube 711.

Specifically, the second heat exchange assembly 70 is provided with a steam-water separation assembly at a position of 50% or more of the height of the second vertical heat exchange tube inside the at least one second vertical heat exchange tube 711. The steam-water separation assembly forms at least axial blocking for at least part of the steam-water fluid, so that the movement direction of the part of the steam-water fluid is increased by a radial component (horizontal direction), the axial movement direction component is reduced, and liquid phase water in the steam-water fluid can form aggregation when touching the steam-water separation assembly, so that the aggregation is separated from water vapor.

Preferably, more than half of or even all of the second vertical heat exchange tubes 711 are provided with steam-water separation components, and the steam-water separation components are arranged in the second vertical heat exchange tubes 711, so that no downpipe is required. More preferably, the second heat exchange assembly 70 is positioned above 70% of the height of the second vertical heat exchange tubes. The steam-water separation assembly is configured to form a fluid barrier to steam-water flow at least partially along the length of the second vertical heat exchange tubes 711 and has a fluid flow path with an upper end for fluid output and a lower end for fluid input. The length of the steam-water separation assembly along the length direction of the second vertical heat exchange tube is more than 1% of the length of the second vertical heat exchange tube 711 and less than 30% of the length of the second vertical heat exchange tube 711, or the length along the length direction of the second vertical heat exchange tube 711 is 5mm-500mm.

Illustrative examples are: the steam-water separation assembly comprises a supporting core rod and a spiral plate. The second vertical heat exchange tube 711 is sleeved outside the support core rod, the spiral plate extends between the support core rod and the second vertical heat exchange tube 711 in a spiral manner along the length direction of the second vertical heat exchange tube 711, and the spiral plate is connected to the outer wall of the support core rod and/or the inner wall of the second vertical heat exchange tube 711. The lower end of the supporting core rod is provided with a boiling stopping plate and/or the upper end of the supporting core rod is provided with a steam outlet plate. The spiral plate extends spirally between the boiling stop plate and the steam outlet plate. The boiling stop plate is provided with an inflow hole for fluid to enter the fluid flow path. The steam outlet plate is provided with a steam outlet hole for outputting fluid. The outlet holes and the inlet holes respectively penetrate the steam outlet plate and the boiling stopping plate along the axial direction, and the shapes of the steam outlet holes and the inlet holes can be round holes, rectangular holes, triangular holes, long holes or other regular or irregular holes, and the present disclosure is not limited in particular.

Further, in order to improve the gas-liquid separation and the boiling stopping effect, the total area of the inflow holes of the boiling stopping plate is smaller than the total area of the outflow holes of the steam outlet plate. The total area of the inflow holes is 3% to 50% of the inner cross-sectional area of the second vertical heat exchange pipe 711, and further, 5% to 30%.

The steam-water separation component in the embodiment forms primary separation of the steam-water fluid in the second vertical heat exchange tube, so that a large amount of water is separated from the steam-water fluid, and the steam dryness is improved. The steam-water separation assembly is integrally positioned at the upper end of the inside of the second vertical heat exchange tube, keeps separation with the liquid-phase water storage in the second vertical heat exchange tube, and a sufficient evaporation space can be reserved between the steam-water separation assembly and the liquid-phase water storage, so that the liquid-phase water can be fully evaporated to form steam, and then the steam-water separation assembly performs steam-water separation.

The level gauge of the steam generating apparatus of the present embodiment is provided at the evaporation heat exchanger (the second heat exchange assembly 70), and the evaporation heat exchanger is built-in with a steam-water separation assembly such as an orifice plate or a spiral separation assembly, thereby improving the steam quality.

In the above description, the first water pump 10 is connected upstream of the first water inlet end. The water inlet end of the first water pump 10 is externally supplied with water, which can be communicated with a water inlet container. The water inlet container can be provided by an external water tank, a water tower or a water tank, and the disclosure is not limited. The head of the first water pump 10 is configured to be greater than the water resistance of the third heat exchange assembly. The second water pump 40 is connected between the first water outlet end and the second water inlet end, and the lift of the second water pump 40 is greater than that of the first water pump 10. For example, the lift of the first water pump 10 is greater than 5m and less than 9m, and the lift of the second water pump 40 is greater than 80m, so as to ensure the water supplementing efficiency and the steam output efficiency.

The first water pump 10, the condensing heat exchanger (one embodiment of the third heat exchange assembly 20), the second water pump 40, the first heat exchange assembly 50, and the second heat exchange assembly 70 (the evaporating heat exchanger) are sequentially (sequentially) connected in series. The water flows through the first water pump 10, the third heat exchange assembly 20 and the second water pump 40 in sequence and enters the first heat exchange assembly 50 and the second heat exchange assembly 70.

In this embodiment, the internal geometric volume (water volume) of the steam generating device from the water outlet end of the second water pump 40 to the steam output end of the first heat exchange assembly 50 is 50L or less, more preferably, the water volume of the steam generating device is 30L or less. To reduce the water volume, the first heat exchange assembly 50 and the second heat exchange assembly 70 are both vertical pipe heat exchange structures, no other heat exchange structures are arranged between the two heat exchange assemblies, the second heat exchange assembly 70 is directly communicated with the downstream of the first heat exchange assembly 50, and no other intermediate heat exchange mechanisms are arranged between the two heat exchange assemblies.

The first water pump 10 is a fixed frequency pump, and the second water pump 40 is a variable frequency pump. Specifically, the second water pump 40 may be a multistage centrifugal variable frequency water pump to provide a larger head and form a pressurized water path downstream thereof. Illustratively, the first water pump 10 employs a 6 m-lift fixed frequency pump, and the second water pump 40 employs a 150 m-lift booster pump (variable frequency pump). The upstream waterway of the second water pump 40 is a normal pressure pipeline (non-pressure-bearing pipeline), and the downstream waterway thereof is a pressure-bearing pipeline.

The heat exchange units of the first heat exchange assembly 50 are a plurality of first vertical heat exchange tubes arranged in the circumferential direction in a single circle. The first vertical heat exchange tube is internally provided with a main heat exchange flow channel, and the outside is provided with a first flue gas flow channel. The first flue gas flow channel communicates with the flue gas output 55. The first heat exchange assembly 50 is provided with only a single turn of vertical heat exchange tubes to reduce the water volume. The flue gas output 55 comprises a flue gas output opening provided on a side wall of the cylindrical housing of the first heat exchange assembly 50. Correspondingly, a flue gas input 74 butted with the flue gas output 55 is arranged on one side of the shell 700 of the second heat exchange assembly 70.

In this embodiment, the first heat exchange unit of the first heat exchange assembly 50 is an annular vertical tube array structure, and the second heat exchange unit 710 of the second heat exchange assembly 70 is a fork-row vertical tube array. The second vertical heat exchange tubes 711 in the second heat exchange assembly 70 are arranged in a crossed manner, so that the smoke flow path and smoke resistance are increased, and the heat exchange efficiency is improved.

As shown in fig. 7, the heat exchange tubes 711 are arranged in a cross manner along the direction from the flue gas inlet to the flue gas outlet (the left-right direction in fig. 7, the overall flue gas flow direction of the second flue gas flow channel), and the second heat exchange tubes 711 are arranged in a plurality of rows, that is, the second heat exchange assembly 70 has a plurality of heat exchange tube rows 750. Each row of heat exchange tubes (each heat exchange tube row 750) is perpendicular to the overall flue gas flow direction. There is a flow gap 712 between two adjacent second vertical heat exchange tubes 711. Among the two heat exchange tube rows 750, the heat exchange tubes 711 of one heat exchange tube row 750 are opposite to the flow gaps 712 between the two heat exchange tubes 711 of the other heat exchange tube row 750 along the overall flue gas flow direction.

The steam generating device of this embodiment sets up the steam generating section in the lower evaporation heat exchanger position of flue gas temperature, and the flue gas passes through first heat exchange assembly 50, avoids working medium to produce clear vapour-water interface in high temperature flue gas district, leads to pipe wall temperature to rise, influences the heat exchanger life-span. In addition, the steam heat exchange equipment of the embodiment adopts a full premix combustion system, the cylindrical burner is matched with the cylindrical through-flow type first heat exchange component, and the flame radiation and high-temperature flue gas convection heat exchange effect is better.

In another possible embodiment, the steam generating device is a coil steam generator. The heat exchange unit of the first heat exchange assembly is of a single-layer coil pipe structure. The single-layer coil is spirally wound to form a cylindrical heat exchange unit. The steam generating apparatus of the present embodiment may further employ a fin tube (fin coil) to increase a heat exchange area as much as possible under a limited water volume, thereby improving heat efficiency and evaporation capacity. In the embodiment of the coiled pipe type steam generator, the steam-water boundary of the single-layer coiled pipe heat exchange unit is not obvious due to the existence of the spiral flow channel structure, and steam-water mixed fluid can be directly output, so that the second water inlet end of the first heat exchange component can be arranged at the upper end of the first heat exchange component, and the second water outlet end is arranged at the lower end of the first heat exchange component; or the second water inlet end of the first heat exchange assembly can be arranged at the lower end of the first heat exchange assembly, and the second water outlet end is arranged at the upper end of the first heat exchange assembly;

With the above description in mind, one end of the burner (the upper end of the burner in fig. 1, 2 and 3) communicates with a fan 60, and the fan 60 communicates with a gas valve. The fan 60 has a gas inlet and an air inlet, the air inlet being in communication with the filter, the gas inlet being in communication with the gas valve. Also provided within the first heat exchange assembly 50 are an ignition means, such as an ignition needle, for igniting the burner and a flame detector, such as a flame probe, for sensing the flame of the burner. The ignition part and the flame detector are fixedly arranged on the bottom plate of the combustion space.

When the second water pump 40 is communicated with the downstream of the third heat exchange assembly 20, the third heat exchange assembly 20 preheats cold water, the preheated water temperature can reach more than 70 degrees or 80 degrees, so that gas in the water is separated out and even gasified to generate a large amount of gas to flow together, and the research finds that the gas is easy to gather at the second water pump 40 to form bubble gas clusters, so that cavitation problem is not only formed, the service life of the pump is influenced, but also the pumping efficiency of the second water pump 40 is reduced, the water cannot be timely supplied to a furnace body, the liquid level of the furnace body is unstable, and the stable gas production cannot be ensured. Although an exhaust valve (such as a normally closed exhaust valve) may be integrated in the second water pump 40, there are still untimely conditions for the exhaust in the event of a large amount of gas generation.

In order to avoid the above problems, in this embodiment, a buffer container 30 having a water containing space therein is further connected between the water inlet end of the third heat exchange assembly 20 and the water inlet end of the second water pump 40. The warm water enters the water containing space to gather and slowly flow, and gas is separated out and prevented from entering the second water pump 40. Wherein, the buffer container 30 is further provided with a communication structure 35 for communicating the water containing space with the outside at least when the internal water level thereof is lower than a preset water level. The communication structure 35 has a function of exhausting air, and thus may also be referred to as an exhaust structure. The water containing space provides a containing space for water after heat exchange with the flue gas or heat exchange, and correspondingly, the separated gas is gathered and released in the water containing space. In addition, the communication structure 35 can always have a gas release and accumulation space above the liquid surface when a certain water level is not reached (for example, water is not fully stored), so that the gas is discharged. The buffer container 30 and the third heat exchange assembly are both communicated with the downstream of the first water pump 10, the pressure head of the first water pump 10 is smaller than 1Bar, and then the third heat exchange assembly and the buffer container 30 are not pressurized.

More preferably, the communication structure 35 is kept in communication with the outside when the water level is low, and is a normally open structure, so that the release of gas can be outwards escaped without opening pressure, and even if the communication structure is applied to a scene with larger gas flow precipitation, the problem that the gas enters the second water pump 40 to cause idling and water supplementing is difficult still does not exist.

In this embodiment, the buffer container 30 is connected to the upstream of the second water pump 40 and the downstream of the third heat exchange assembly, that is, the buffer container 30 is connected between the water inlet end of the second water pump 40 and the water inlet end of the third heat exchange assembly. The communication structure 35 is communicated with the outside atmosphere at least when the internal water level of the water containing space is lower than a preset water level. The preset water level may be 70% or more of the water containing space, and the preset water level may be 100% of the water level, that is, the communication structure 35 is closed under the condition of full water, so as to form a closed water containing space. As the pressure in the water containing space increases due to the suction of the second water pump 40 and the gas extraction, the water level in the water containing space gradually decreases until the communication structure 35 (automatic exhaust valve) is opened again.

In this embodiment, the buffer container 30 is a tank structure, which stores warm water after heat exchange with flue gas or heat exchange, and a thermal insulation measure is provided outside the buffer container 30 in order to avoid heat dissipation. The buffer container 30 has a volume of 1L to 500L, and further, the buffer container 30 has a volume of 20L to 50L. The communication structure 35 is configured to communicate with the atmosphere when the water level is lower than a predetermined water level and to be disconnected from the atmosphere when the water level is higher than the predetermined water level.

It can be appreciated that the buffer container 30 is opened in a water-free state or a water-less state, and the communication structure 35 is kept open during the water input process, so that the gas can escape without pressure, the air content of the water in the second water pump 40 is reduced, and the hidden trouble that the water cannot be supplemented due to the idle running of the second water pump 40 is eliminated.

Specifically, the communication structure 35 is a normally open type exhaust valve 35 (for example, a normally open type automatic exhaust valve) provided at the upper end of the buffer container 30. The communication structure 35 is located at a height of 70% or more from the inner bottom surface of the buffer container 30. As shown in fig. 2 and 4, the exhaust valve 35 is mounted on the top of the buffer container 30, the exhaust valve 35 may be provided with a float linked with the plugging valve core, and when the liquid level rises to a predetermined liquid level (water level), the float floats to drive the plugging valve core to close the exhaust valve 35, so as to avoid the buffer container 30 overflowing outwards. The second water pump 40 is communicated with the buffer container 30, and water in the buffer container 30 is pumped by the second water pump 40, so that the risk of idle cavitation of the second water pump 40 due to large air quantity can be avoided. Of course, in order to avoid water leakage caused by excessive water inflow, the communication structure 35 is preferably a normally open type automatic vent valve 35.

As shown in fig. 2 and 3, the third heat exchange assembly 20 is a condensation heat exchanger for recovering the flue gas waste heat at the flue gas output end of the first heat exchange assembly 50. The first fluid flow passage comprises an inner flow passage of a condensing heat exchange tube in the condensing heat exchanger, and the second flue gas flow passage is limited in the condensing heat exchanger shell and is positioned between the condensing heat exchange tube and the condensing heat exchanger shell. The condensing heat exchanger is in communication with a first water pump 10 that drives the flow of fluid. The first water pump 10 is connected in series between the water inlet joint (the apparatus water inlet end) and the water inlet end (the first water inlet end) of the first fluid flow path. The condensing heat exchanger housing 21 has a flue gas inlet 23 (flue gas input) which communicates with a flue gas output 72 of the second heat exchange assembly 70. The top of the condensing heat exchanger shell 21 has a smoke outlet 28 (smoke output). The condensing heat exchanger is provided with a first water inlet end and a first water outlet end, and a plurality of condensing heat exchange tubes connected in series or in parallel are limited between the first water inlet end and the first water outlet end. The first water inlet end is communicated with the water outlet end of the first water pump 10 through a first pipeline, and the water inlet end of the first water pump 10 is communicated with a water inlet joint so as to input external cold water.

In the present embodiment, the buffer container 30 is a buffer water storage tank that is connected to the upstream side of the second water pump 40 and the downstream side of the third heat exchange unit 10. The height of the buffer water storage tank is lower than that of the condensing heat exchanger, and the buffer water storage tank is arranged below the condensing heat exchanger. The height of the buffer water storage tank is more than 0.2m and less than 1.5 m; the cross section area of the water containing space of the buffer water storage tank is more than 100 square centimeters. For example, the water containing space of the buffer container 30 is a cylindrical cavity having a diameter of between 100 and 300mm and a height of about 500mm (+ -100 mm).

The water inlet end of the second water pump 40 is communicated with the water outlet end (water outlet interface) of the buffer water storage tank through a pipeline 35, and the water inlet end of the buffer water storage tank is communicated with the first water outlet end of the third heat exchange assembly through a pipeline 25. The water outlet end of the second water pump 40 is in communication with the second water inlet end 52 of the first heat exchange assembly 50 via a conduit 45. The second water inlet end 52 is disposed at the upper end of the first heat exchange assembly 50. The second water outlet 53 is disposed at the lower end of the first heat exchange assembly 50. The flue gas output end 55 is disposed on a side wall of the first heat exchange assembly 50, forms a flue gas outlet, and is fixedly connected with a flue gas inlet 74 of the second heat exchange assembly 70 through a flange. The lower header bottom of the first heat exchange assembly 50 is also provided with a drain pipe 54.

It should be noted that, regarding the structures of the first heat exchange assembly 50, the buffer container 30, the first water pump 10, the second water pump 40, and the third heat exchange assembly 20, reference may also be made to the description of the chinese patent application with publication number CN115614722a filed by the applicant on the year 2022, month 10, and 15, entitled "steam generating apparatus and operation method thereof", and the repetition is omitted.

Any numerical value recited herein includes all values of the lower and upper values that are incremented by one unit from the lower value to the upper value, as long as there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of components or the value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, then the purpose is to explicitly list such values as 15 to 85, 22 to 68, 43 to 51, 30 to equivalent values in this specification as well. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be explicitly recited in this description, and all possible combinations of values recited between the lowest value and the highest value are believed to be explicitly stated in the description in a similar manner.

Unless otherwise indicated, all ranges include endpoints and all numbers between endpoints. "about" or "approximately" as used with a range is applicable to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the indicated endpoints.

All articles and references, including patent applications and publications, disclosed herein are incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not substantially affect the essential novel features of the combination. The use of the terms "comprises" or "comprising" to describe combinations of elements, components, or steps herein also contemplates embodiments consisting essentially of such elements, components, or steps. By using the term "may" herein, it is intended that any attribute described as "may" be included is optional.

Multiple elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, component, section or step is not intended to exclude other elements, components, sections or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated herein by reference for the purpose of completeness. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to forego such subject matter, nor should the inventors regard such subject matter as not be considered to be part of the disclosed subject matter.

Claims

1. A steam generating apparatus, comprising:

a burner;

2. The steam generating apparatus of claim 1, wherein the second heat exchange assembly is provided with a boiler water level gauge.

3. The steam generating apparatus of claim 1, wherein a third heat exchange assembly is further provided; the third heat exchange assembly is limited with a third flue gas flow passage and a preheating flow passage; the third flue gas flow channel is communicated with the downstream of the second flue gas flow channel in the flue gas flow direction; the preheating flow passage is communicated with the upstream of the main heat exchange flow passage in the water flow direction; and the water in the preheating flow passage exchanges heat with the smoke in the third smoke flow passage to heat and preheat.

4. The steam generating apparatus of claim 1, wherein the third heat exchange assembly is a condensing heat exchanger having a first water inlet end and a first water outlet end; a first water pump is communicated with the upstream of the first water inlet end;

5. The steam generating apparatus of claim 1, wherein the first heat exchange assembly comprises a cylindrical housing, and a first heat exchange unit inside the cylindrical housing; the first heat exchange unit is communicated between the second water inlet end and the second water outlet end; the first heat exchange unit is limited with a plurality of first vertical heat exchange pipes of the main heat exchange flow channel, and the first vertical heat exchange pipes surround the combustion chamber where the combustor burns.

6. The steam generating apparatus of claim 1, wherein the first heat exchange assembly is further provided with an inner rod inside at least one of the first vertical heat exchange tubes; a water storage space is formed between the outer wall of the inner rod and the inner wall of the heat exchange tube; the length of the inner rod along the length direction of the heat exchange tube is more than 20% of the length of the heat exchange tube.

7. The steam generating apparatus of claim 1, wherein the second heat exchange assembly comprises a housing and a second heat exchange unit located within the housing; the second heat exchange unit includes a plurality of second vertical heat exchange tubes defining the steam generation flow passage; the second heat exchange assembly is provided with a third water inlet end communicated with the second water inlet end; the third water inlet end is positioned at the lower end of the second heat exchange unit.

8. The steam generating apparatus of claim 1, wherein an upper header communicating with a steam output is provided at an upper end of the second heat exchange assembly, and a lower header communicating with the third water inlet is provided at a lower end of the second heat exchange assembly; the upper ends of the second vertical heat exchange tubes are communicated with the upper header, and the lower ends of the second vertical heat exchange tubes are communicated with the lower header.

9. The steam generating apparatus of claim 1, wherein the second heat exchange assembly is provided with a steam-water separation assembly inside the at least one second vertical heat exchange tube at a position above 50% of the height of the second vertical heat exchange tube; the steam-water separation assembly is configured to form a steam-water fluid barrier for at least partially flowing along the length direction of the heat exchange tubes and has a fluid flow path with an upper end for fluid output and a lower end for fluid input; the length of the steam-water separation component along the length direction of the heat exchange tube is more than 1% of the length of the heat exchange tube and less than 30% of the length of the heat exchange tube, or the length along the length direction of the heat exchange tube is 5mm-500mm.

10. The steam generating apparatus of claim 1, wherein the primary heat exchange flow path surrounds the combustion chamber; the steam generation flow passage is positioned outside the first heat exchange assembly.